This invention relates to improved packages, and more particularly to improved multilayer bags.
Several important difficulties are encountered in packaging articles having sharp edges, points or corners. First, such articles commonly pierce their package from within, endangering persons and property. Paper bags or sacks are particularly defective in this respect. Second, even the most tear resistant bag, while it may reduce to some extent the likelihood of the contained article protruding from within, fails adequately to protect the packaged articles at easily broken points or sharp edges. Padding that might give a degree of protection to the packaged article, and thereby reduce the latter defect to some extent, ordinarly does not resist puncture from within. Clearly, then, packaging sharp and relatively fragile articles inexpensively, in a padded bag, extremely resistant to puncture from within, is desirable.
A further desirable characteristic of bags for packaging such potentially injurous articles is extreme resistance to accidental opening or opening by tiny children. Tear resistance is important even to the degree of making tearing open of the bag virtually impossible.
Multilayer bags are known for various purposes. Padded bags are known wherein a padding or insulating filling material is loosely contained in the bag wall. Bags with inner moisture impervious thermoplastic layers are known. Moreover the formation of a much improved multilayer shipping bag including sheets of polyethylene foam is suggested in copending U.S. patent application Ser. No. 419,923 of John D. Bambara and Dennis Knaus, filed Nov. 27, 1973 and assigned to the assignee of this invention. None of these bags is believed to combine the extreme resistance to puncture from within and to tearing that is afforded by the invention described below.